Method of operating furnaces



H. E. YARROW.

METHOD 0F OPERATING FURNACES.

APPLICATION FILED APR.6,1920.

242%046; Patented Aug. 22, 1922;

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5H. E. YARRDW.

METHODOF OPERATING FURNACES.

APPLICATIQN man APR.5. 1920.

1,42%@46 Patented Aug. 22., w22.

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zaezz/Zof E, arrow f@ /M /m v f 'Warizg HAROLD E. YARROW, OF GLASGOW, SCOTLAND.

METHOD OE OPERATING FURNACES.

Lisanne.

Specification of Letters Patent.

Patented Aug. 22, i922.

Application led April 6, 1920. Serial No. 371,744.

To @ZZ whom t may concern:

De it known that I, HAROLD EDGAR Yannow, a subject of the King of Great Britain, residing in Glasgow, Scotland, have invented certain new and useful Methods of perating` Furnaces, of which the following is a specilication.

Where automatic stokers are used for the grates of furnaces and the fuel is fed at one end ofthe grate and travels to the other end, there is a certain section of the grate which is liable to be over-heated and burnt out, especially in arrangements where the air supply to the furnace is preheated.

This section is situated at about the centre of the grate; the ends are less heated at the front of the grate because the unburnt fuel is fed in there, and at the other end because most of the combustible material has been consumed and the grate is covered with ashes.

To remove the danger of overheating any portion of the grate surface in installations of this kind using preheated air, according to the invention the heated air is only supplied to the ends of the grate, and the cen tral section Where the combustion is most intense is fed with cold air. y

rlhe accompanying drawing shows an eX- ample of the arrangement according to the invention as applied to a travelling grate of a boiler of the Yarrow type, but the system is applicable to any furnace in which the fuel is automatically carried from one end to the other of the grate.

F ig. l is a side view of the boiler with parts in section;

Fig. 2 is a cross-section, the left-hand side of same being taken on the line 22, Fig. l, and the right hand side of same being taken on the line 2-2, F ig. l;

Fig. 3 is a cross-section takeny on the line 3 3, Fig. l; and

Fig. d is a partial section on the line 4 4, Fig. 3.

A is the steam and water drum; B B water drums; C the travelling grate; and D E F sections of the grate area, of which the end sections D and F are supplied with hot air through ducts Gr and G', respectively, as shown in F ig. 2. rThese ducts may be in connection with a chamber leading to the uptake and heated by the furnace gases. The central section E of the grate area is supplied withk cold air through ducts H, as shown in Fig. 3. Partition plates J divide the grate area into the sections D E F. The ducts may be of any convenient form. For example, the central duct may be in the form of a truncated cone, Wider at the bottom than at the top. The particular means for heating the air is well known and forms no part of the present invention.

The part of the partition between the upper and lower portions of the travelling grate may be made of thin plate, and the part below the grate either of plate vor brickwork. il small quantity of air leaking in either direction through the openings in the partitions separating the various sections would not affect the results obtained by the method of the invention.

l-laving thus described the nature of the said invention and the best means l know of carrying the saine into practical eect, l claim:-

A method of operating a furnace, which consists in moving the lire bed progressively therethrough, in heating air and supplying the same to the end. portions of the lire bed from beneath, and in supplying cold air to the central portion of the lire bed from beneath.

In testimony whereof l have signed my naine to this specification.

HAROLD E. YARRO. 

